not sure if this is what you mean, but on this page:
At the bottom of the editable example, add the line "showButton: true" to the code snippet as follows -
titleTemplate: "Invalid value",
messageTemplate: "Valid values are 'true' and 'false'."
Then if you preview the example and click one of the cells in the true/false column, you will see the dropdown arrow next to it allowing you to select one of the cell items in the range as demonstrated in the example.